Abstract: The thermal stability of Fiber Bragg Gratings （FBGs） is an important topic in its applications in telecommunications. In the present work, the mechanism of the stability of FBGs is interpreted. Based on the Master Curve approach, we develop a valid program to improve the stability and prediction of the future life of FBGs under certain conditions. The experimental result on the FBGs fabricated by 244nm CW-UV laser in a H₂ loaded telecommunication fiber is provided. The example for determining the annealing condition and predicting the life of component is given. The results can refer to the applications of FBGs in the telecommunications.